Hydraulic systems commonly employ pressure and return ports for connection to a hydraulic pressure source and a tank. With these systems, a worker may routinely connect and disconnect pressure and return lines to the pressure and return ports of the hydraulic system. When the pressure and return connections are made properly, the system operates normally, but when the pressure and return connections are inadvertently reversed, the hydraulic system can be severely damaged.
Typically, the hydraulic pressure source itself will include a pressure relief valve for guarding against reversed connections. For example, in a trailer truck having a reciprocating floor conveyor, the hydraulic system of the truck usually includes a relief valve for protecting against reversed connections to the pressure and return lines of the conveyor's hydraulic drive system.
However, the pressure relief valve of the truck's hydraulic system sometimes is set inadvertently too high, and either the conveyor drive system operates in reverse, due to reversed connections, or the system is damaged. The present invention is directed toward alleviating this problem.